package day1020;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class Test4 {

    public static void main(String[] args) {



        Set  s=new HashSet();//无序
        s.add("张三");
        s.remove("张三");
        for (Object o : s) {

        }



        Map  s2=new HashMap();//无序
        s2.put("张三",1);
        s2.remove("张三");
        for (Object e  :   s2.entrySet()){

        }














    }

}









